Problem Solving

A certain meter records voltage both 0 and 10 inclusive. If average(arithmetic mean) value of 3 recordings on meter was 8 volts, what was smallest possible recording in volts?
A)2 B)3 C)4 D)5 E)6

gayu wrote:A certain meter records voltage both 0 and 10 inclusive. If average(arithmetic mean) value of 3 recordings on meter was 8 volts, what was smallest possible recording in volts?
A)2 B)3 C)4 D)5 E)6

average of 3 recordings is 8 volts; therefore sum of three recordings =24
now work with the options;
a)if minimum number is 2; then sum of the remaining two numbers should be 22; which is not possible as the maximum that each number can take is 10;
b) if minimum value is 3; then sum of the remaining two numbers should be 21; which is not possible as the maximum value that each number can take is 10.
c) if minimum value is 4; then sum of the remaining two numbers should be 20, now this is possible, here each of the remaining two numbers can take 10 each..

hence C